the relationship between students' study habits, happiness and depression

background : one of the important requirements for cultural, social and even economic development is having a book-loving nation. in order to achieve this, there is a need for purposeful and continuous programming. the purpose of this research was to determine the relationship between students' study habits, happiness and depression in isfahan university of medical science. methods : this research was a kind of descriptive and correlation survey. statistical population included all msc and phd students in the second semester of the isfahan university of medical science (263 students). in this research, stratified and random sampling was used in which a sample of 100 students was selected. data collection instruments were beck depression inventory (bdi), oxford happiness inventory and a researcher-made questionnaire to determine the amount of students' study. validity of this questionnaires was determined by structure and content related validity and its reliability was calculated by cronbach's alpha coefficient for the first (r = 0.94), second (r = 0.91) and third (r = 0.85) questionnaire. analysis of research findings was done through descriptive and inferential statistics. results : findings showed that 68.8 percent of students study less than 5 hours and only 2.5 percent of students study more than 10 hours. 65 percent of students had high amount of happiness and 35 percent had medium amount of happiness. in 60 percent of students there was no symptom of depression and 7.5 had depression symptoms. also, there was no significant relationship between happiness and studying but there was a significant and negative relationship between studying and depression and happiness and depression. conclusions : the amount of study and tendency for reading are among the most important indices of human growth in terms of potential abilities for achieving a perfect human life and to prevent one-dimensional thinking. thus, finding ways to encourage students to study is considered essential to achieve a healthy and developed society. key words : students' study habits, depression, happiness.